Photographic developer containing an antifogging agent



Patented May I1, 1937 UNITED" STATES PHOTOGBAPHIC DEVELO PER AN ANTIFOGGING AGENT Cyril J. "some and Merle L. Damion. Rochester,

N. Y., assignors, by mesne assignments, to

Eastman Kodak Company, Jersey City, N. 1., a corporation of New Jersey No Drawing.S

This invention relates to photographic developers, and more particularly to photographic developers containing antifogging agents. It is known that under certain conditions, fogging occurs during the development of a photographic plate or film. Even though the developer has been properly made up, if the developing agent has become oxidized, or ii the temperature rises above 70 or if the development is continued 1 for an extended time, fogging is apt to occur.

We have discovered that the addition to a developer of a small amount of an iodo substituted saturated aliphatic carboxylic acid containing less than nine carbon atoms, such, for

instance, as iodoacetic acid or beta-iodopropionic acid, greatly decreases the amount of fogging taking place in the developer. Preferably, the iodo-acid is added to the developer just before development. The use of these acids as anti fogging agents has been disclosed .in Patent No. 1,954,337 of Cyril J. Staud, one oi! the applicants in the present case.

The lode-acid may be introduced into the developer indirectly by incorporating it in an antihalation backing or in the light-sensitive emulsion of the photographic film or plate, or it may be added directly to the developingbath.

To illustrate the application of .our invention and its eiiect, several examples-will be given;

Example I Photographic plates not sensitized with. any dye, were exposed behind'a trl-color sensitometer with a No. 79 Wratten light filter (a bluish illter wave lengths below 360 The developer used was one for producing high contrast, and was made up as follows:

The plates were developed in individual trays of this developer, to whichiodoacetic acid had been freshly added in the amounts of 0, 20, and 200 mgm. per 100 cc. of developer. Development was carried. out at 68 F. for 8 minutes,- and the following results were obtained: a

6 Concentration of iodoacetic acid Bpeed Gamma Fog m 3. 1 76 m 1 7 15 m 2. 6 Ii 741 1 U 21 which cuts out most of the ultra-violet new; of

Application July 5.19s erial No. 29,971

6 Claims. (CL- -40) From this table it is evident that the presence of iodoacetic acid in the developer brings about a marked decrease in fog, accompanied by an increase in sensitivity and a slight less in contrast. It is also apparent that in this case 20 mgm. 0!

iodoacetlc acid had practically the same effect as 200 mgm. 1

Fog was also decreased when the iodoacetic acid was added to the developer 1 hours before the development.

Example 11 Spectroscopic plates sensitized to the infra-red by tricarbocyanines were hypersensitized in ammonia, exposed, and developed in the developer described above, to which iodoacetic acid had been added in amounts of 0 and 50 mgm. per cc. of developer. The plates developed in the developer containing iodoacetic acid showed practically the same sensitivity as the control, but amarked decrease in fog.

Example III Plates not sensitized with any dye were developed for five minutes at temperatures of 51, 68 and 86" 1". in the developer described above. to which iodoacetic acid hadvbeen added in amounts of (land 100 mm. per 100 cc. of developer. The results obtained were as follows:

No iodoecetic acid in 100 mm. iodosoetic acid 'le pndevelops per 100 cc. developer tureot developmt Speed Gamma Fog Speed Gamma Fog l. 51 676 .92 .N 575 .28 .[B 8.. me 2. .2! 715 1.9 12 U 485 ass m 3.62 -.M

I Thus itwlll be seen that even at abnormally high temperatures of development, the presence of the taking place, while not appreciably decreasing the contrast. 7

' Example IV 1 The materials and procedure were the same as in Example 1, except that beta-iodopropionic acid was used in place of iodoacetic acid. The

viollt'm'ins results were obtained:

mum of bets-iod mionic eeid Speed iodo-scid greatly decreases the amount of fogging crease in fog. The increase in sensitivity is not so great as in Example I, but there is no loss in contrast.

What we claim as our invention and desire to be secured by Letters Patent 0! the United States is: a

1. A photographic developer containing an iodo substituted saturated aliphatic carboxylic acid containing less than nine carbon atoms, in an amount sumcient todecrease fogging during .development.

2. A phophic developer containing iodoacetic acid in an amount sumcientto decrease fogging during development.

3. A photographic developer containing betaecon? 20 milligr of beta-iodopropionic acid per 100 cc. of developer.

I 1-: il' J. STAUD. L. DUNDON.

iodopropionic acid in an amolmt' suficient to 

